Process for the preparation of 2-amino-4-chloro-1,3,5-triazines

ABSTRACT

Compounds of the formula (I) or salts thereof                  
 
are suitable for preparing active substances from the from the class of the aminotriazines of the formula (IV), for example herbicidal active substances. The compounds (I) can be prepared by chlorinating compounds of the formula (II)                  
 
where, in the formulae, R 1 , R 2 , R 3  and X are as defined in claim 1 and A and R have the meaning required in the active substances to be prepared, and they can be reacted with amines of the formula A—NH—R to give the active substances.

This application is a 371 of PCT/EP99/04581, filed Jul. 2, 1999.

The invention relates to the technical field of the chemical synthesisof bioactive compounds, preferably the processes for the preparation ofcrop protection agents and intermediates for these processes.

It has been disclosed that 2-amino-4-chloro-1,3,5-triazines which aresubstituted by organic radicals in the 6-position on the triazine ringcan be employed for preparing bioactive aminotriazines, for exampleherbicidal aminotriazines, the chlorine atom being exchanged for anN-substituted amino radical; cf. WO-A-90/09378, WO-A-96/25404,WO-A-97/00254, WO-A-97/08156, WO-A-97/19936, WO-A-97/29095,WO-A-97/31904, WO-A-97/35481, WO-A-98/10654, WO-A-98/15536,WO-A-98/15537, WO-A-98/15538, WO-A-98/15539; moreover, aminotriazineshave been proposed in International Application No. PCT/EP98/00283 andin German Patent Application No. 19826670.7.

The substituted 2-amino-4-chloro-1,3,5-triazines can be obtained inaccordance with a known process from the suitably substituted2,4-dichloro-1,3,5-triazines and ammonia, or amines [J. Med. Chem. 12(1969) 41, J. Am. Chem. Soc. 82 (1960) 3760]. The 6-substituted2,4-dichloro-1,3,5-triazines, which are employed as starting compoundsfor this purpose, can be prepared, for example, from cyanuric chlorideand Grignard compounds which are substituted in the 6-position on thetriazine ring like the organic radical [Helv. Chim. Acta 33 (1950)1368]. Alternatively, they can be synthesized from trichloromethylisocyanide dichloride and amidines which are substituted in the6-position on the triazine ring like the organic radical (cf.DE-A-1178437).

The disadvantages of the known processes are the limited availability,in particular the lack of availability of the Grignard compounds for thepreparation of triazines with alkyl radicals in the 6-position, andfrequently poor yields when reacting the dichlorotriazines with ammoniaor amines.

It is an object of the invention to prepare in an alternative andpreferably advantageous manner 2-amino-4-chloro-1,3,5-triazines whichhave unsubstituted or substituted aliphatic hydrocarbon radicals in the6-position. This is also intended to make available some novel triazinesof the formula (I).

The invention relates to a process for the preparation of compounds ofthe formula (I) or salts thereof

in which

-   -   R¹ is (C₁–C₈)alkyl or (C₃–C₈)cycloalkyl, where each of the two        above radicals independently of the other is unsubstituted or        substituted, preferably unsubstituted or substituted by one or        more radicals selected from the group consisting of halogen,        hydroxyl, cyano, nitro, thiocyanato, formyl, (C₁–C₈)alkoxy,        (C₁–C₈)alkylthio, (C₁–C₈)alkylsulfinyl, (C₁–C₈)alkylsulfonyl,        [(C₁–C₈)-alkyl]carbonyl, [(C₁–C₈)alkoxy]carbonyl,        (C₂–C₈)alkenyl, (C₂–C₈)alkynyl, (C₃–C₈)cycloalkyl, phenyl and,        in the case of cycloalkyl, also (C₁–C₈)alkyl, each of the        last-mentioned 11 radicals being unsubstituted or substituted by        one or more radicals selected from the group consisting of        halogen, (C₁–C₄)alkoxy, (C₁–C₄)alkylthio and, in the case of        cyclic radicals, also (C₁–C₄)alkyl and (C₁–C₄)haloalkyl, and    -   R², R³ in each case independently of one another are hydrogen,        amino, hydroxyl, formyl or unsubstituted or substituted        (C₁–C₈)alkyl, (C₁–C₈)alkylamino, di[(C₁–C₈)alkyl]amino,        (C₁–C₈)alkyloxy, aryl, aryloxy, (C₃–C₈)cycloalkyl,        [(C₁–C₈)alkyl]carbonyl, [(C₁–C₈)alkoxy]carbonyl, arylcarbonyl,        aryloxycarbonyl, (C₁–C₈)alkylsulfonyl, arylsulfonyl or an        unsubstituted or substituted heterocyclyl radical,        heterocyclyloxy radical, heterocyclylamino radical, each of        which has 3 to 6 ring atoms and 1 to 3 hetero ring atoms        selected from the group consisting of N, O and S, or    -   R², R³ together with the nitrogen atom of the group NR²R³ are a        heterocyclic radical having 3 to 6 ring atoms and 1 to 4 hetero        ring atoms, where, in addition to the nitrogen atom, the other        hetero ring atoms which may exist are selected from the group        consisting of N, O and S and the heterocycle is unsubstituted or        substituted.        which comprises converting 2-amino-4-thio-1,3,5-triazines of the        general formula (II)        in which X represents hydrogen, (C₁–C₆)alkyl, (C₂–C₆)alkenyl,        (C₂–C₆)alkynyl or phenyl, where each of the last-mentioned 4        radicals is unsubstituted or substituted, or represents a        2-amino-4-thio-1,3,5-triazine radical which is bonded via sulfur        and equally substituted by chlorination into the compound (I).

The 2-amino-4-thio-1,3,5-triazines (II), which act as startingmaterials, are known or can be prepared analogously to known processes[cf. DE-A-4139624, Chem. Ber. 100 (1967) 1874–1891, J. HeterocyclicChem. 27 (1990) 1565–1568, J. Heterocyclic Chem. 23 (1986) 1709–1714].

A chlorinating agent is required in the process according to theinvention, for example chlorine, salts of hypochlorous acid, phosphoruspentachloride, phosphoryl chloride (=phosphorus oxychloride) or thionylchloride, preferably chlorine.

The chlorinating agent is employed, for example, in amounts of 1 to 100equivalents based on the compound of the formula (II), preferably 1 to10 equivalents, in particular in equimolar amounts up to an excess,which allows a reaction of the compound of the formula (II) to takeplace. An equivalent in this context is to be understood as meaning suchan amount of chlorinating agent which is required for reacting thecompound (II) according to stoichiometrical reasons.

In principle, the chlorination reaction can be carried out withoutadditional solvent and/or diluent (hereinbelow both: solvent), or, mostexpediently, in the presence of a solvent. Suitable solvents arepreferably organic solvents which are largely inert to the chlorinatingagent and the compounds of the formulae (II) and (I) under the reactionconditions. Examples of suitable solvents are:

1. Predominantly aprotic organic solvents which are inert under thereaction conditions, for example

-   -   aliphatic and aromatic hydrocarbons such as, for example,        mineral oils, petroleum ether, cyclohexane or toluene, xylenes,        naphthalene derivatives, ®Solvesso 200 (high-boiling aromatic        mixture);    -   halogenated aliphatic and aromatic hydrocarbons such as        methylene chloride, dichloroethane, chloroform or chlorobenzene;    -   cyclic or open-chain ethers such as diethyl ether, di-n-propyl        ether, diisopropyl ether, methyl tert-butyl ether,        tetrahydrofuran (THF), dioxane, alkylene glycol monoalkyl ethers        and alkylene glycol dialkyl ethers such as, for example,        propylene glycol monomethyl ether, propylene glycol monoethyl        ether, ethylene glycol monomethyl ether or ethylene glycol        monoethyl ether, dimethoxyethane, diglyme, triglyme and        tetraglyme;    -   amides such as dimethylformamide (DMF), dimethylacetamide and        N-methylpyrrolidone;    -   ketones such as cyclohexanone, methyl isobutyl ketone (MIBK);    -   nitriles such as acetonitrile, propionitrile, butyronitrile and        benzonitrile;    -   sulfoxides are sulfones such as dimethyl sulfoxide (DMSO) and        sulfolane,    -   carboxylic esters such as the esters of mono-, di- and        tricarboxylic acids with aliphatic alcohols having 1 to 10        carbon atoms, for example ethyl formate, methyl acetate, ethyl        acetate, n-propyl acetate, i-propyl acetate, esters of acetic        acid with n-, i-, sec- or tert-butanol,    -   mixtures of two or more of the abovementioned solvents;

2. Essentially anhydrous, preferably largely anhydrous, protic solventsand their mixtures or mixtures with the abovementioned aprotic solvents.Examples of protic solvents are

-   -   aliphatic alcohols such as methanol, ethanol, n- or i-propanol,        n-, i-, sec- or tert-butanol, glycols;    -   carboxylic acids, for example those having 1 to 4 carbon atoms        such as formic acid, acetic acid, n-propionic acid or n- and        isobutanoic acid.

If the compounds of the formula (II) are chlorinated with chlorine,especially suitable solvents are, for example, methylene chloride,chloroform and concentrated acetic acid, preferably the correspondinganhydrous solvents such as, for example, glacial acetic acid.

The reaction can be carried out within a wide temperature range, in somecases depending on the substrate, the chlorinating agent and thesolvent, for example at temperatures between −40° C. and the boilingpoint of the solvent in question, preferably between −20° C. and 100°C., in particular between 0° C. and 50° C. The reaction temperatureshould be low enough to avoid side reactions, but high enough to allow aconversion within technically feasible reaction times.

As regards the pressure, particular conditions are not required; as arule, it is possible or expedient to carry out the chlorination reactionunder atmospheric pressure.

Generally customary methods may be employed for working up the reactionmixture. After the reaction, it is possible, for example, to pass aninert gas, for example nitrogen gas, through the mixture so as to removeexcess chlorine gas, and subsequently to pour the reaction mixture intowater. The product is separated from the water and dried. If thechlorination reaction is carried out in the presence of solvents whichare miscible with water, such as, for example, carboxylic acids, thereaction mixture is preferably put into an aqueous solution of a base.If the chlorination reaction is carried out in the presence of solventswhich are not miscible with water such as, for example, halogenatedhydrocarbons, a base which is not soluble in this solvent is preferablyadded to the reaction mixture after chlorination, and the mixture isfiltered and the product separated from the solvent and dried. Suitablebases are customary organic and, preferably, inorganic bases, andaqueous solutions of these, for example hydroxides or carbonates ofalkali metals or alkaline earth metals.

Some chlorination reactions of 2-amino-4-alkylthio-1,3,5-triazines arealready known, but the triazines are substituted by aromatic radicals inthe 6-position on the triazine ring. Thus, chlorination reactions forthe preparation of 2,4-dichloro-6-(2-pyridyl)-1,3,5-triazine[Tetrahedron 31 (1975) 1879–1882] or of2-chloro-4,6-bis(2′,4′-dimethylphenyl)-1,3,5-triazine [U.S. Pat. No.5,084,570] from the corresponding alkylthio-1,3,5-triazines have alreadybeen described. The conditions for the chlorination reaction which aregiven in the known protocols cannot be simply used for the2-amino-4-thio-1,3,5-triazines of the formula (II) which haveunsubstituted or substituted alkyl radicals in the 6-position. Incontrast to aromatic radicals in the 6-position, thealkylthio-1,3,5-triazines which have unsubstituted or substitutedaliphatic radicals in the 6-position and which are employed inaccordance with the invention generally require milder chlorinationconditions. Moreover, the amino group in the 2-position can sometimeslead to undesired side reactions and thus to yield losses or lowerproduct purities when using the known chlorination conditions.

With a view to the use of the compounds (I) as intermediates for thesynthesis of active substances, the radical R¹ preferably has thefollowing meaning:

-   -   R¹ is (C₁–C₆)alkyl which is unsubstituted or substituted by one        or more radicals selected from the group consisting of halogen,        hydroxyl, cyano, nitro, thiocyanato, formyl, (C₁–C₄)alkoxy,        (C₁–C₄)alkylthio, (C₁–C₄)alkylsulfinyl, (C₁–C₄)alkylsulfonyl,        [(C₁–C₄)alkyl]carbonyl, [(C₁–C₄)alkoxy]carbonyl, (C₂–C₄)alkenyl,        (C₂–C₄)alkynyl, (C₃–C₆)cycloalkyl, phenyl, where each of the        last-mentioned 10 radicals is unsubstituted or substituted by        one or more radicals selected from the group consisting of        halogen, (C₁–C₄)alkoxy, (C₁–C₄)alkylthio and, in the case of        cyclic radicals, also (C₁–C₄)alkyl and (C₁–C₄)haloalkyl.    -   R¹ is preferably also (C₃–C₆)cycloalkyl which is unsubstituted        or substituted by one or more radicals selected from the group        consisting of halogen, hydroxyl, cyano, nitro, thiocyanato,        formyl, (C₁–C₄)alkyl, (C₁–C₄)alkoxy, (C₁–C₄)alkylthio,        (C₁–C₄)alkylsulfinyl, (C₁–C₄)alkylsulfonyl,        [(C₁–C₄)alkyl]carbonyl, [(C₁–C₄)alkoxy]carbonyl, (C₂–C₄)alkenyl,        (C₂–C₄)alkynyl, (C₃–C₆)cycloalkyl, phenyl, where each of the        last-mentioned 11 radicals is unsubstituted or substituted by        one or more radicals selected from the group consisting of        halogen, (C₁–C₄)alkoxy, (C₁–C₄)alkylthio and, in the case of        cyclic radicals, also (C₁–C₄)alkyl and (C₁–C₄)haloalkyl.    -   R¹ is especially preferably (C₁–C₆)alkyl which is unsubstituted        or substituted by one or more radicals selected from the group        consisting of halogen, preferably fluorine, chlorine or bromine,        hydroxyl, methoxy, ethoxy and cyclopropyl.    -   R¹ is especially preferably also (C₃–C₆)cycloalkyl which is        unsubstituted or substituted by one or more radicals selected        from the group consisting of halogen, preferably fluorine,        chlorine or bromine, hydroxyl, (C₁–C₄)alkoxy, preferably methoxy        and ethoxy, (C₁–C₄)alkyl, preferably methyl and ethyl, and        (C₁–C₄)haloalkyl, preferably CF₃.    -   R², R³ are preferably in each case independently of one another        hydrogen, amino, (C₁–C₆)alkyl, (C₁–C₄)alkylamino,        di[(C₁–C₄)alkyl]amino, (C₁–C₄)alkyloxy, (C₃–C₆)cycloalkyl,        (C₁–C₄)alkyl]carbonyl, [(C₁–C₄)alkoxy]carbonyl, phenylcarbonyl,        phenoxycarbonyl, (C₁–C₄)alkylsulfonyl, phenylsulfonyl or a        heterocyclyl radical having 3 to 6 ring atoms and 1 to 3 hetero        ring atoms selected from the group consisting of N, O and S,        where phenyl in the abovementioned radicals or the heterocyclyl        radical independently of one another are unsubstituted or        substituted by one or more radicals selected from the group        consisting of halogen, preferably fluorine, chlorine or bromine,        hydroxyl, (C₁–C₄)alkoxy, preferably methoxy and ethoxy,        (C₁–C₄)alkyl, preferably methyl and ethyl, and (C₁–C₄)haloalkyl,        preferably CF₃, or    -   R², R³ together with the nitrogen atom of the group NR²R³ is a        heterocyclic radical which has 3 to 6 ring atoms and 1 to 3        hetero ring atoms, where, in addition to the nitrogen atom, the        other hetero ring atoms which may be present are selected from        the group consisting of N, O and S and the heterocycle is        unsubstituted or substituted by one or more radicals selected        from the group consisting of halogen, preferably fluorine,        chlorine or bromine, hydroxyl, (C₁–C₄)alkoxy, preferably methoxy        and ethoxy, (C₁–C₄)alkyl, preferably methyl and ethyl, and        (C₁–C₄)haloalkyl, preferably CF₃.

The radicals R², R³ in each case independently of one another arepreferably hydrogen, amino, methyl, ethyl, acetyl.

The compounds of the formula (I) can form salts when a basic group suchas, for example, amino or alkylamino, undergoes an addition reactionwith a suitable inorganic or organic acid such as, for example, HCl,HBr, H₂SO₄ or HNO₃, but also oxalic acid or sulfonic acids.

With a view to the use of the compounds (II) as intermediates for thesynthesis of active substances, the radical X has, for example, thefollowing meaning:

-   -   X is, for example, hydrogen, (C₁–C₆)alkyl, (C₂–C₆)alkenyl or        (C₂–C₆)alkynyl, where each of the last-mentioned 3 radicals is        unsubstituted or substituted by one or more radicals selected        from the group consisting of halogen, (C₁–C₄)alkoxy,        (C₁–C₄)alkylthio, (C₁–C₄)alkylsulfinyl, (C₁–C₄)alkylsulfonyl,        [(C₁–C₄)alkyl]carbonyl, [(C₁–C₄)alkoxy]carbonyl,        (C₃–C₆)cycloalkyl and phenyl, each of the last-mentioned 10        radicals being unsubstituted or substituted by one or more        radicals selected from the group consisting of halogen,        (C₁–C₄)alkoxy, (C₁–C₄)alkylthio and, in the case of cyclic        radicals, also (C₁–C₄)alkyl and (C₁–C₄)haloalkyl or represents        phenyl which is unsubstituted or substituted by one or more        radicals selected from the group consisting of halogen, cyano,        nitro, (C₁–C₄)alkyl, (C₁–C₄)alkoxy, (C₁–C₄)alkylthio,        (C₁–C₄)alkylsulfinyl, (C₁–C₄)alkylsulfonyl,        [(C₁–C₄)alkyl]carbonyl, [(C₁–C₄)alkoxy]carbonyl, (C₂–C₄)alkenyl,        (C₂–C₄)alkynyl, (C₃–C₆)cycloalkyl, each of the last-mentioned 10        radicals being unsubstituted or substituted by one or more        radicals selected from the group consisting of halogen,        (C₁–C₄)alkoxy, (C₁–C₄)alkylthio and, in the case of cyclic        radicals, also (C₁–C₄)alkyl and (C₁–C₄)haloalkyl, or represents        a 2-amino-4-thio-1,3,5-triazine radical which is bonded via        sulfur and equally substituted,    -   X preferably represents (C₁–C₄)alkyl which is unsubstituted or        substituted by one or more radicals selected from the group        consisting of halogen, (C₁–C₄)alkoxy, (C₁–C₄)alkylthio,        (C₃–C₆)cycloalkyl and phenyl, each of the last-mentioned 4        radicals being unsubstituted or substituted by one or more        radicals selected from the group consisting of halogen,        (C₁–C₄)alkoxy, (C₁–C₄)alkylthio and, in the case of cyclic        radicals, also (C₁–C₄)alkyl and (C₁–C₄)haloalkyl, or    -   represents phenyl which is unsubstituted or substituted by one        or more radicals selected from the group consisting of halogen,        cyano, nitro, (C₁–C₄)alkyl, (C₁–C₄)haloalkyl, (C₁–C₄)alkoxy,        (C₁–C₄)haloalkoxy, (C₁–C₄)alkylthio and [(C₁–C₄)alkoxy]carbonyl,        or    -   represents a 2-amino-4-thio-1,3,5-triazine radical which is        bonded via sulfur and equally substituted,    -   X represents, in particular, (C₁–C₄)alkyl, benzyl or phenyl,        where each of the last-mentioned two groups is unsubstituted in        the phenyl moiety or substituted by one or more radicals        selected from the group consisting of halogen, cyano, nitro,        (C₁–C₄)alkyl, preferably methyl, (C₁–C₄)haloalkyl, preferably        CF₃ or CCl₃, (C₁–C₄)alkoxy, preferably methoxy,        (C₁–C₄)haloalkoxy, preferably OCHF₂, and (C₁–C₄)alkylthio.

In the abovementioned formulae, the radicals alkyl, alkoxy, haloalkyl,haloalkoxy, alkylamino and alkylthio and the corresponding unsaturatedand/or substituted radicals in the carbon skeleton can in each case bestraight-chain or branched. Unless otherwise specified, the lower carbonskeletons, for example those having 1 to 6 carbon atoms, or in the caseof unsaturated groups, 2 to 6 carbon atoms, are preferred for theseradicals. Alkyl radicals, also in the composite meanings such as alkoxy,haloalkyl and the like, are, for example, methyl, ethyl, n- or i-propyl,n-, i-, t- or 2-butyl, pentyls, hexyls such as n-hexyl, i-hexyl and1,3-dimethylbutyl, heptyls such as n-heptyl, 1-methylhexyl and1,4-dimethylpentyl; alkenyl and alkynyl radicals have the meanings ofthe possible unsaturated radicals which correspond to the alkylradicals; alkenyl is, for example, allyl, 1-methylprop-2-en-1-yl,2-methylprop-2-en-1-yl, but-2-en-1-yl, but-3-en-1-yl,1-methylbut-3-en-1-yl and 1-methylbut-2-en-1-yl; alkynyl is, forexample, propargyl, but-2-yn-1-yl, but-3-yn-1-yl, 1-methylbut-3-yn-1-yl.

Cycloalkyl is a carbocyclic saturated ring system having preferably 3–8carbon atoms, for example cyclopropyl, cyclobutyl, cyclopentyl orcyclohexyl.

Halogen is, for example, fluorine, chlorine, bromine or iodine.Haloalkyl, -alkenyl and -alkynyl are alkyl, alkenyl or alkynyl which arepartially or fully substituted by halogen, preferably by fluorine,chlorine and/or bromine, in particular by fluorine and/or chlorine, forexample monohaloalkyl, perhaloalkyl, CF₃, CHF₂, CH₂F, CF₃CF₂, CH₂FCHCl,CCl₃, CHCl₂, CH₂CH₂Cl; haloalkoxy is, for example, OCF₃, OCHF₂, OCH₂F,CF₃CF₂O, OCH₂CF₃ and OCH₂CH₂Cl; this also applies analogously tohaloalkenyl and other halogen-substituted radicals.

Aryl is a mono-, bi- or polycyclic aromatic system, for example phenyl,naphthyl, tetrahydronaphthyl, indenyl, indanyl, pentalenyl, fluorenyland and the like, preferably phenyl.

A heterocyclic radical or ring (heterocyclyl) can be saturated,unsaturated or heteroaromatic; it preferably contains one or more, inparticular 1, 2 or 3, hetero atoms in the heterocyclic ring, preferablyselected from the group consisting of N, O and S; it is preferably analiphatic heterocyclyl radical having 3 to 7 ring atoms or aheteroaromatic radical having 5 or 6 ring atoms. The heterocyclicradical can be, for example, a heteroaromatic radical or ring(heteroaryl) such as, for example, a mono-, bi- or polycyclic aromaticsystem in which at least 1 ring contains one or more hetero atoms, forexample pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl,thienyl, thiazolyl, thiadiazolyl, oxazolyl, isoxazolyl, furyl, pyrrolyl,pyrazolyl and imidazolyl, or is partially or fully hydrogenated radicalsuch as oxiranyl, pyrrolidyl, piperidyl, piperazinyl, dioxolanyl,oxazolinyl, isoxazolinyl, oxazolidinyl, isoxazolidinyl, morpholinyl,tetrahydrofuryl. Substituents which are suitable for a substitutedheterocyclic radical are the substituents mentioned further below, andadditionally also oxo. The oxo group may also occur on the hetero ringatoms, which may exist in various degrees of oxidation, for example inthe case of N and S.

Substituted radicals such as a substituted alkyl, alkenyl, alkynyl,aryl, phenyl, benzyl, heterocyclyl and heteroaryl radical, are, forexample, a substituted radical derived from the unsubstituted parentstructure, the substituents being, for example, one or more, preferably1, 2 or 3, radicals selected from the group consisting of halogen,alkoxy, haloalkoxy, alkylthio, hydroxyl, amino, nitro, carboxyl, cyano,azido, alkoxycarbonyl, alkylcarbonyl, formyl, carbamoyl, mono- anddialkylaminocarbonyl, substituted amino such as acylamino, mono- anddialkylamino, and alkylsulfinyl, haloalkylsulfinyl, alkylsulfonyl,haloalkylsulfonyl and, in the case of cyclic radicals, also alkyl andhaloalkyl; the term “substituted radicals” such as substituted alkyl andthe like includes, as substituents, in addition to the abovementionedsaturated hydrocarbon-containing radicals the corresponding unsaturatedaliphatic and aromatic radicals, such as unsubstituted or substitutedalkenyl, alkynyl, alkenyloxy, alkynyloxy, phenyl, phenoxy and the like.In the case of radicals having carbon atoms, those having 1 to 4 carbonatoms, in particular 1 or 2 carbon atoms, are preferred. Preferred are,as a rule, substituents selected from the group consisting of halogen,for example fluorine and chlorine, (C₁–C₄)alkyl, preferably methyl orethyl, (C₁–C₄)haloalkyl, preferably trifluoromethyl, (C₁–C₄)alkoxy,preferably methoxy or ethoxy, (C₁–C₄)haloalkoxy, nitro and cyano.Especially preferred in this context are the substituents methyl,methoxy and chlorine.

The formula (I) and (II) also encompass all stereoisomers. Suchcompounds contain one or more asymmetric carbon atoms or else doublebonds which are not mentioned specifically in the formulae. Thestereoisomers which are possible and which are defined by their specificspatial form, such as enantiomers, diastereomers, Z- and E-isomers, canbe obtained by customary methods from mixtures of the stereoisomers orelse be prepared by stereoselective reactions in combination with theuse of stereochemically pure starting materials.

It is preferred to react the compounds (I) with amines of the formula(III)A—NH—R  (III),with exchange of the chlorine atom, to give herbicidal aminotriazines ofthe formula (IV)

where, in formulae (III) and (IV), the radicals R¹, R², R³ are asdefined in formula (I) and A and R are radicals which in conjunctionwith the remaining molecular structure of the formula (IV) constitutethe chemical structure of a herbicidally active aminotriazine.

The herbicidal aminotriazines are preferably those from the publicationsWO-A-90/09378, WO-A-96/25404, WO-A-97/00254, WO-A-97/08156,WO-A-97/19936, WO-A-97/29095, WO-A-97/31904, WO-A-97/35481,WO-A-98/10654, WO-A-98/15536, WO-A-98/15537, WO-A-98/15538,WO-A-98/15539, the International Application No. PCT/EP98/00283 and theGerman Patent Application No. 19826670.7, which have already beenmentioned at the outset, but the radicals R¹, R² and R³ are as definedin the abovementioned process according to the invention. The definitionof the herbicidal aminotriazines from the publications is specificallyincorporated by reference; they are thus part of the presentdescription.

In formula (IV), the radical A is preferably a (C₁–C₆)alkylene chainwhich is substituted in the α-position relative to the amino group by anunsubstituted or substituted alkyl radical and in the ω-position by anunsubstituted or substituted aryl, heteroaryl, aryloxy or heteroaryloxyradical and which can also have further substituents selected from thegroup consisting of halogen, alkyl, alkoxy and hydroxyl.

R is preferably H or alkyl such as (C₁–C₄)alkyl, in particular H.

Especially preferred are the preferred herbicidal aminotriazines whichare mentioned in the above publications, in particular the compoundswhich are in each case defined specifically, such as the preparationexamples and the individually defined tabulated examples, as long as theradicals which correspond to the radicals R¹, R² and R³ in formula (IV)are defined within the scope of the present invention.

The invention therefore also relates to a process for the preparation ofherbicidal aminotriazines of the formula (IV), which comprises firstpreparing, in accordance with the invention, a compound of the formula(I) and then reacting it with an amine of the formula (III) to give thecompound of the formula (IV).

Reaction conditions for reacting the compounds of the formulae (I) and(III) are known in principle from the publications mentioned inconnection with the herbicidal aminotriazines (IV) and from theliterature cited therein, or can be carried out analogously to thestandard reactions known to the skilled worker for reactingheteroaromatic chlorine compounds with amines.

The invention generally also relates to the use of compounds of theformula (I) or salts thereof which have been obtained by the processaccording to the invention for the preparation of the compounds (I) forthe preparation of bioactive substances from the chemical class of theaminotriazines, preferably the herbicidal aminotriazines.

In the examples which follow, quantities are by weight unless otherwisespecified. Conventional abbreviations are used for units and physicalquantities, for example

-   h=hour(s), m.p.=melting point, l=liter, g=gram, min=minute(s), in    vacuo=under reduced pressure

EXAMPLES

a) 2-Amino-4-methylthio-6-(1-fluoroisopropyl)-1,3,5-triazine

125 g of 2-fluoroisobutyroyl chloride and 300 ml of triethylamine weresimultaneously added dropwise (0.5 h) at approx. 20° C. to a solution of245 g of S-methylguanylisothiourea methylsulfate and 250 g of sodiumsulfate in 1 liter of anhydrous N-methylpyrrolidone. After the reactionmixture had been stirred for 3 h at 50° C., the cooled mixture waspoured into 5 liters of water. The crude product which has precipitatedis filtered off with suction and extracted by stirring with heptane.After filtration with suction and drying, 150 g (75%) of2-amino-4-methylthio-6-(1-fluoroisopropyl)-1,3,5-triazine were obtainedas a white powder (m.p. 155° C.).

¹H NMR (CDCl₃): δ=1.7 (d, 6H), 2.5 (s, 3H), 5.7 (s br., 1H), 6.9 (s br.,1H).

b) 2-Amino-4-chloro-6-(1-fluoroisopropyl)-1,3,5-triazine (Table 1,Example 25)

Chlorine gas was passed at 20 to 25° C. into a suspension of 150 g of2-amino-4-methylthio-6-(1-fluoroisopropyl)-1,3,5-triazine in 1 liter ofglacial acetic acid (15 min). The reaction mixture was stirred for 30min at approx. 20° C., flushed with nitrogen gas for 1 h at roomtemperature, poured into 5 liters of ice-cold aqueous solution of 350 gof sodium hydroxide and stirred for 5 min. After filtration with suctionand drying, 110 g (80%) of2-amino-4-chloro-6-(1-fluoroisopropyl)-1,3,5-triazine were obtained as awhite powder (m.p. 185° C.).

¹H NMR (CDCl₃): δ=1.7 (d, 6H), 6.2 (s br., 1H), 6.9 (s br., 1H).

c) 2-Amino-4-chloro-6-(1-fluoroethyl)-1,3,5-triazine (Table 1, Example21)

Chlorine gas was passed into a suspension of 38 g of2-amino-4-methylthio-6-(1-fluoroethyl)-1,3,5-triazine in 0.25 l ofglacial acetic acid (15 min) at 20 to 25° C. The reaction mixture wasstirred for 30 min at approx. 20° C., sprayed for 1 hour with nitrogengas at room temperature, poured into 1.25 l of ice-cold aqueous solutionof 87 g of sodium hydroxide and stirred for 5 min. After extraction withethyl acetate, the organic phase was washed with water and dried overmagnesium sulfate, and the solvent was removed in vacuo. The crudeproduct was purified by stirring in heptane. After filtration withsuction and drying, 25 g (70%) of2-amino-4-chloro-6-(1-fluoroethyl)-1,3,5-triazine were obtained as awhite powder (m.p. 131° C.); ¹H NMR (CDCl₃): δ=1.7 (dd, 3 H), 5.4 (dq, 1H), 6.1 (s br., 1 H), 6.7 (s br., 1H).

d) 2-Amino-4-chloro-6-trifluoromethyl-1,3,5-triazine (Table 1, Example15)

Chlorine gas was passed into a solution of 21 g of2-amino-4-methylthio-6-trifluoromethyl-1,3,5-triazine in 0.2 l glacialacetic acid at 20 to 25° C. (15 min). The reaction mixture was stirredfor 30 min at approx. 20° C., sprayed for 1 hour with nitrogen gas atroom temperature, poured into 1 l of ice-cold aqueous solution of 70 gof sodium hydroxide and stirred for 5 min. After extraction with ethylacetate, the organic phase was washed with water and dried overmagnesium sulfate, and the solvent was removed in vacuo. The crudeproduct was purified by stirring in heptane. After filtration withsuction and drying, 12 g (60%) of2-amino-4-chloro-6-trifluoromethyl-1,3,5-triazine were obtained as awhite powder (m.p. 109° C.); ¹H NMR (CDCl₃): δ=6.4 (s br., 2H).

e) 2-Amino-4-chloro-6-(1-chloroisopropyl)-1,3,5-triazine (Table 1,Example 32)

Chlorine gas was passed at 20 to 25° C. into a suspension of 110 g of2-amino-4-methylthio-6-(1-chloroisopropyl)-1,3,5-triazine in 0.75 l ofglacial acetic acid (30 min). The reaction mixture was stirred for 30min at approx. 20° C., sprayed with nitrogen gas for 1 h at roomtemperature, poured into 3.75 l of ice-cold aqueous solution of 260 g ofsodium hydroxide and stirred for 5 min. After filtration with suctionand drying, 83 g (80%) of2-amino-4-chloro-6-(1-chloroisopropyl)-1,3,5-triazine were obtained as awhite powder (m.p. 110° C.); ¹H NMR (CDCl₃): δ=1.9 (s, 6 H), 6.0 (s br.,2 H).

f) Comparative example anologous to the chlorination described in U.S.Pat. No. 5,084,570 [conditions for (het)aryl-substituted2-amino-4-alkylthio-1,3,5-triazines]

Chlorine gas was passed at 35 to 40° C. into a solution of 5 g of2-amino-4-methylthio-6-(1-chloroisopropyl)-1,3,5-triazine in 0.1 l oftrichloromethane (or tetrachloromethane) (15 min). 10 g of potassiumcarbonate were added to the reaction mixture at room temperature, andthe mixture was stirred for 5 minutes and filtered and the solventremoved in vacuo. This gave a product mixture in which approximately 0.5g (10%) of 2-amino-4-chloro-6-(1-chloroisopropyl)-1,3,5-triazine arepresent (detection by HPLC comparison with 100% product).

The table which follows shows the abovementioned examples according tothe invention in addition to other examples obtained analogously. Thechlorination products of the formula (I) are obtained, as a rule, inyields of 60 to 95% of theory.

The following abbreviations are used in Table 1 which follows:

-   Me=methyl-   c-Pr=cyclopropyl-   c-Bu=cyclobutyl; n-Bu=n-butyl-   c-Pe=cyclopentyl-   Ac=acetyl

TABLE 1 Compounds of the formula (I)

No. R¹ R² R³ 1 CH₃ H H 2 C₂H₅ H H 3 C₃H₇ H H 4 CH(CH₃)₂ H H 5 c-Pr H H 6n-C₄H₉ H H 7 CH(CH₃)C₂H₅ H H 8 c-Bu H H 9 n-C₅H₁₁ H H 10 c-Pe H H 11CH₂-c-Pr H H 12

H H 13 CH₂F H H 14 CHF₂ H H 15 CF₃ H H 16 CH₂Cl H H 17 CHCl₂ H H 18 CCl₃H H 19 CClF₂ H H 20 CFCl₂ H H 21 CHFCH₃ H H 22 CF₂CH₃ H H 23 CF₂CF₂H H H24 CF₂CF₃ H H 25 CF(CH₃)₂ H H 26 CH(CF₃)CH₃ H H 27 CF(CF₃)CH₃ H H 28CH(CF₃)₂ H H 29 CF(CF₃)₂ H H 30 CHClCH₃ H H 31 CCl₂CH₃ H H 32 CCl(CH₃)₂H H 33 CFCl—CH₃ H H 34

H H 35

H H 36 CH₂OCH₃ H H 37 CH(CH₃)OCH₃ H H 38 C(CH₃)₂OCH₃ H H 39 C₂H₅OCH₃ H H40 CH(CH₃)CH₂OCH₃ H H 41

H H 42 CH₂OH H H 43 CH(CH₃)OH H H 44 C(CH₃)₂OH H H 45 C₂H₅OH H H 46CH(CH₃)CH₂OH H H 47

H H 48 CH₃ Me H 49 C₂H₅ Me H 50 C₃H₇ Me H 51 CH(CH₃)₂ Me H 52 c-Pr Me H53 n-C₄H₉ Me H 54 CH(CH₃)C₂H₅ Me H 55 c-Bu Me H 56 n-C₅H₁₁ Me H 57 c-PeMe H 58 CH₂-c-Pr Me H 59

Me H 60 CH₂F Me H 61 CHF₂ Me H 62 CF₃ Me H 63 CH₂Cl Me H 64 CHCl₂ Me H65 CCl₃ Me H 66 CClF₂ Me H 67 CFCl₂ Me H 68 CHFCH₃ Me H 69 CF₂CH₃ Me H70 CF₂CF₂H Me H 71 CF₂CF₃ Me H 72 CF(CH₃)₂ Me H 73 CH(CF₃)CH₃ Me H 74CF(CF₃)CH₃ Me H 75 CH(CF₃)₂ Me H 76 CF(CF₃)₂ Me H 77 CHClCH₃ Me H 78CCl₂CH₃ Me H 79 CCl(CH₃)₂ Me H 80 CFCl—CH₃ Me H 81

Me H 82 Me H 83 CH₂OCH₃ Me H 84 CH(CH₃)OCH₃ Me H 85 C(CH₃)₂OCH₃ Me H 86C₂H₅OCH₃ Me H 87 CH(CH₃)CH₂OCH₃ Me H 88

Me H 89 CH₂OH Me H 90 CH(CH₃)OH Me H 91 C(CH₃)₂OH Me H 92 C₂H₅OH Me H 93CH(CH₃)CH₂OH Me H 94

Me H 95 CH₃ Me Me 96 C₂H₅ Me Me 97 C₃H₇ Me Me 98 CH(CH₃)₂ Me Me 99 c-PrMe Me 100 n-C₄H₉ Me Me 101 CH(CH₃)C₂H₅ Me Me 102 c-Bu Me Me 103 n-C₅H₁₁Me Me 104 c-Pe Me Me 105 CH₂-c-Pr Me Me 106

Me Me 107 CH₂F Me Me 108 CHF₂ Me Me 109 CF₃ Me Me 110 CH₂Cl Me Me 111CHCl₂ Me Me 112 CCl₃ Me Me 113 CClF₂ Me Me 114 CFCl₂ Me Me 115 CHFCH₃ MeMe 116 CF₂CH₃ Me Me 117 CF₂CF₂H Me Me 118 CF₂CF₃ Me Me 119 CF(CH₃)₂ MeMe 120 CH(CF₃)CH₃ Me Me 121 CF(CF₃)CH₃ Me Me 122 CH(CF₃)₂ Me Me 123CF(CF₃)₂ Me Me 124 CHClCH₃ Me Me 125 CCl₂CH₃ Me Me 126 CCl(CH₃)₂ Me Me127 CFCl—CH₃ Me Me 128

Me Me 129

Me Me 130 CH₂OCH₃ Me Me 131 CH(CH₃)OCH₃ Me Me 132 C(CH₃)₂OCH₃ Me Me 133C₂H₅OCH₃ Me Me 134 CH(CH₃)CH₂OCH₃ Me Me 135

Me Me 136 CH₂OH Me Me 137 CH(CH₃)OH Me Me 138 C(CH₃)₂OH Me Me 139 C₂H₅OHMe Me 140 CH(CH₃)CH₂OH Me Me 141

Me Me 142 CH₃ Ac H 143 C₂H₅ Ac H 144 C₃H₇ Ac H 145 CH(CH₃)₂ Ac H 146c-Pr Ac H 147 n-C₄H₉ Ac H 148 CH(CH₃)C₂H₅ Ac H 149 c-Bu Ac H 150 n-C₅H₁₁Ac H 151 c-Pe Ac H 152 CH₂-c-Pr Ac H 153

Ac H 154 CH₂F Ac H 155 CHF₂ Ac H 156 CF₃ Ac H 157 CH₂Cl Ac H 158 CHCl₂Ac H 159 CCl₃ Ac H 160 CClF₂ Ac H 161 CFCl₂ Ac H 162 CHFCH₃ Ac H 163CF₂CH₃ Ac H 164 CF₂CF₂H Ac H 165 CF₂CF₃ Ac H 166 CF(CH₃)₂ Ac H 167CH(CF₃)CH₃ Ac H 168 CF(CF₃)CH₃ Ac H 169 CH(CF₃)₂ Ac H 170 CF(CF₃)₂ Ac H171 CHClCH₃ Ac H 172 CCl₂CH₃ Ac H 173 CCl(CH₃)₂ Ac H 174 CFCl—CH₃ Ac H175

Ac H 176

Ac H 177 CH₂OCH₃ Ac H 178 CH(CH₃)OCH₃ Ac H 179 C(CH₃)₂OCH₃ Ac H 180C₂H₅OCH₃ Ac H 181 CH(CH₃)CH₂OCH₃ Ac H 182

Ac H 183 CH₂OH Ac H 184 CH(CH₃)OH Ac H 185 C(CH₃)₂OH Ac H 186 C₂H₅OH AcH 187 CH(CH₃)CH₂OH Ac H 188

Ac H 189 CH₃ NH₂ H 190 C₂H₅ NH₂ H 191 C₃H₇ NH₂ H 192 CH(CH₃)₂ NH₂ H 193c-Pr NH₂ H 194 n-C₄H₉ NH₂ H 195 CH(CH₃)C₂H₅ NH₂ H 196 c-Bu NH₂ H 197n-C₅H₁₁ NH₂ H 198 c-Pe NH₂ H 199 CH₂-c-Pr NH₂ H 200

NH₂ H 201 CH₂F NH₂ H 202 CHF₂ NH₂ H 203 CF₃ NH₂ H 204 CH₂Cl NH₂ H 205CHCl₂ NH₂ H 206 CCl₃ NH₂ H 207 CClF₂ NH₂ H 208 CFCl₂ NH₂ H 209 CHFCH₃NH₂ H 210 CF₂CH₃ NH₂ H 211 CF₂CF₂H NH₂ H 212 CF₂CF₃ NH₂ H 213 CF(CH₃)₂NH₂ H 214 CH(CF₃)CH₃ NH₂ H 215 CF(CF₃)CH₃ NH₂ H 216 CH(CF₃)₂ NH₂ H 217CF(CF₃)₂ NH₂ H 218 CHClCH₃ NH₂ H 219 CCl₂CH₃ NH₂ H 220 CCl(CH₃)₂ NH₂ H221 CFCl—CH₃ NH₂ H 222

NH₂ H 223

NH₂ H 224 CH₂OCH₃ NH₂ H 225 CH(CH₃)OCH₃ NH₂ H 226 C(CH₃)₂OCH₃ NH₂ H 227C₂H₅OCH₃ NH₂ H 228 CH(CH₃)CH₂OCH₃ NH₂ H 229

NH₂ H 230 CH₂OH NH₂ H 231 CH(CH₃)OH NH₂ H 232 C(CH₃)₂OH NH₂ H 233 C₂H₅OHNH₂ H 234 CH(CH₃)CH₂OH NH₂ H 235

NH₂ H

1. A process for the preparation of compounds of the formula (I) orsalts thereof

in which R¹ is (C₁–C₈)alkyl or (C₃–C₈)cycloalkyl, which is independentlyof one another unsubstituted or substituted by one or more radicalsselected from the group consisting of halogen, hydroxyl, cyano, nitro,thiocyanato, formyl, (C₁–C₈)alkoxy, (C₁–C₈)alkylthio,(C₁–C₈)alkylsulfinyl, (C₁–C₈)alkylsulfonyl, [(C₁–C₈)-alkyl]carbonyl,[(C₁–C₈)alkoxy]carbonyl, (C₃–C₈)cycloalkyl, phenyl and, in the case ofcycloalkyl, also (C₁–C₈)alkyl, each of the last-mentioned 9 radicalsbeing unsubstituted or substituted by one or more radicals selected fromthe group consisting of halogen, (C₁–C₄)alkoxy, (C₁–C₄)alkylthio and, inthe case of cyclic radicals, also (C₁–C₄)alkyl and (C₁–C₄)haloalkyl, andR²,R³ in each case independently of one another are hydrogen, amino,(C₁–C₆)alkyl, (C₁–C₄)alkylamino, di[(C₁–C₄)alkyl]amino, (C₁–C₄)alkyloxy,(C₃–C₆)cycloalkyl, [(C₁–C₄)alkyl]carbonyl, [(C₁–C₄)alkoxy]carbonyl,phenylcarbonyl, phenoxycarbonyl, (C₁–C₄)alkylsulfonyl, phenylsulfonyl ora saturated heterocyclyl radical having 3 to 6 ring atoms and 1 to 3hetero ring atoms selected from the group consisting of N, O and S,where phenyl in the abovementioned radicals or the heterocyclyl radicalindependently of one another are unsubstituted or substituted by one ormore radicals selected from the group consisting of halogen, hydroxyl,(C₁–C₄)alkoxy, (C₁–C₄)alkyl, and (C₁–C₄)haloalkyl, or R²,R³ togetherwith the nitrogen atom of the group NR²R³ is a saturated heterocyclicradical which has 3 to 6 ring atoms and 1 to 3 hetero ring atoms, where,in addition to the nitrogen atom, the other hetero ring atoms which maybe present are selected from the group consisting of N, O and S and theheterocycle is unsubstituted or substituted by one or more radicalsselected from the group consisting of halogen, hydroxyl, (C₁–C₄)alkoxy,(C₁–C₄)alkyl and (C₁–C₄)haloalkyl, which comprises converting2-amino-4-thio-1,3,5-triazines of the formula (II)

in which X represents (C₁–C₄)alkyl which is unsubstituted or substitutedby one or more radicals selected from the group consisting of halogen,(C₁–C₄)alkoxy, (C₁–C₄)alkylthio, (C₃–C₆)cycloalkyl and phenyl, each ofthe last-mentioned 4 radicals being unsubstituted or substituted by oneor more radicals selected from the group consisting of halogen,(C₁–C₄)alkoxy, (C₁–C₄)alkylthio and, in the case of cyclic radicals,also (C₁–C₄)alkyl and (C₁–C₄)haloalkyl, or represents phenyl which isunsubstituted or substituted by one or more radicals selected from thegroup consisting of halogen, cyano, nitro, (C₁–C₄)alkyl,(C₁–C₄)haloalkyl, (C₁–C₄)alkoxy, (C₁–C₄)haloalkoxy, (C₁–C₄)alkylthio and[(C₁–C₄)alkoxy]carbonyl, or represents a 2-amino-4-thio-1,3,5-triazineradical which is bonded via sulfur and equally substituted, bychlorination in the presence of an essentially anhydrous protic solvent.2. The process as claimed in claim 1, wherein R¹ is (C₁–C₆)alkyl whichis unsubstituted or substituted by one or more radicals selected fromthe group consisting of halogen, hydroxyl, cyano, nitro, thiocyanato,formyl, (C₁–C₄)alkoxy, (C₁–C₄)alkylthio, (C₁–C₄)alkylsulfinyl,(C₁–C₄)alkylsulfonyl, [(C₁–C₄)alkyl]carbonyl, [(C₁–C₄)alkoxy]carbonyl,(C₃–C₆)cycloalkyl, phenyl, where each of the last-mentioned 8 radicalsis unsubstituted or substituted by one or more radicals selected fromthe group consisting of halogen, (C₁–C₄)alkoxy, (C₁–C₄)alkylthio and, inthe case of cyclic radicals, also (C₁–C₄)alkyl and (C₁–C₄)haloalkyl, or(C₃–C₆)cycloalkyl which is unsubstituted or substituted by one or moreradicals selected from the group consisting of halogen, hydroxyl, cyano,nitro, thiocyanato, formyl, (C₁–C₄)alkyl, (C₁–C₄)alkoxy,(C₁–C₄)alkylthio, (C₁–C₄)alkylsulfinyl, (C₁–C₄)alkylsulfonyl,[(C₁–C₄)alkyl]carbonyl, [(C₁–C₄)alkoxy]carbonyl, (C₂–C₄)alkenyl,(C₂–C₄)alkynyl, (C₃–C₆)cycloalkyl, phenyl, where each of thelast-mentioned 11 radicals is unsubstituted or substituted by one ormore radicals selected from the group consisting of halogen,(C₁–C₄)alkoxy, (C₁–C₄)alkylthio and, in the case of cyclic radicals,also (C₁–C₄)alkyl and (C₁–C₄)haloalkyl, and R²,R³ in each caseindependently of one another are hydrogen, amino, (C₁–C₆)alkyl,(C₁–C₄)alkylamino, di[(C₁–C₄)alkyl]amino, (C₁–C₄)alkyloxy,(C₃–C₆)cycloalkyl, [(C₁–C₄)alkyl]carbonyl, [(C₁–C₄)alkoxy]carbonyl,phenylcarbonyl, phenoxycarbonyl, (C₁–C₄)alkylsulfonyl, phenylsulfonyl ora saturated heterocyclyl radical having 3 to 6 ring atoms and 1 to 3hetero ring atoms selected from the group consisting of N, O and S,where phenyl in the abovementioned radicals or the heterocyclyl radicalindependently of one another are unsubstituted or substituted by one ormore radicals selected from the group consisting of halogen, hydroxyl,(C₁–C₄)alkoxy, (C₁–C₄)alkyl, and (C₁–C₄)haloalkyl, or R²,R³ togetherwith the nitrogen atom of the group NR²R³ is a saturated heterocyclicradical which has 3 to 6 ring atoms and 1 to 3 hetero ring atoms, where,in addition to the nitrogen atom, the other hetero ring atoms which maybe present are selected from the group consisting of N, O and S and theheterocycle is unsubstituted or substituted by one or more radicalsselected from the group consisting of halogen, hydroxyl, (C₁–C₄)alkoxy,(C₁–C₄)alkyl and (C₁–C₄)haloalkyl.
 3. The process as claimed in claim 1,wherein a chlorinating agent selected from the group consisting ofchlorine, salts of hypochlorous acid, phosphorus pentachloride,phosphoryl chloride and thionyl chloride is employed.
 4. The process asclaimed in claim 1, wherein the chlorinating agent is employed in anamount of 1 to 100 equivalents based on the compound of the formula(II).
 5. The process as claimed in claim 1, which is carried out in thepresence of an aprotic or essentially anhydrous protic solvent ormixtures of these.
 6. The process as claimed in claim 5 which is carriedout at temperatures between −40° C. and the boiling point of the solventor mixtures of solvents employed.
 7. The process as claimed in claim 1,which is carried out at temperatures between 0° C. and 50° C.
 8. Theprocess as claimed in claim 1, wherein said essentially anhydrous proticsolvent is a carboxylic acid.
 9. The process as claimed in claim 1,wherein said essentially anhydrous protic solvent is selected from thegroup consisting of formic acid, acetic acid, n-propionic acid,n-butanoic acid and isobutanoic acid.
 10. The process as claimed inclaim 1, wherein said essentially anhydrous protic solvent is glacialacetic acid.
 11. The process as claimed in claim 1, wherein X is(C₁–C₄)alkyl.
 12. The process as claimed in claim 1, wherein R¹ is(C₁–C₆)alkyl which is unsubstituted or substituted by one or moreradicals selected from the group consisting of halogen, hydroxy,methoxy, ethoxy and cyclopropyl.
 13. The process as claimed in claim 1,wherein R¹ is (C₃–C₆)cycloalkyl which is unsubstituted or substituted byone or more radicals selected from the group consisting of halogen,hydroxyl, (C₁–C₄)alkoxy, (C₁–C₄)alkyl and (C₁–C₄)haloalkyl.
 14. Theprocess of claim 1, wherein X is (C₁–C₄)alkyl, benzyl or phenyl, whereeach of the last-mentioned two groups is unsubstituted in the phenylmoiety or substituted by one or more radicals selected from the groupconsisting of halogen, cyano, nitro, (C₁–C₄)alkyl, (C₁–C₄)haloalkyl,(C₁–C₄)alkoxy, (C₁–C₄)haloalkoxy and (C₁–C₄)alkylthio.
 15. The processas claimed in claim 1, wherein: R¹ is (C₁–C₆)alkyl which isunsubstituted or substituted by one or more radicals selected from thegroup consisting of halogen, hydroxy, methoxy, ethoxy and cyclopropyl;or R¹ is (C₃–C₆)cycloalkyl which is unsubstituted or substituted by oneor more radicals selected from the group consisting of halogen,hydroxyl, (C₁–C₄)alkoxy, (C₁–C₄)alkyl and (C₁–C₄)haloalkyl; X is(C₁–C₄)alkyl, benzyl or phenyl, where each of the last-mentioned twogroups is unsubstituted in the phenyl moiety or substituted by one ormore radicals selected from the group consisting of halogen, cyano,nitro, (C₁–C₄)alkyl, (C₁–C₄)haloalkyl, (C₁–C₄)alkoxy, (C₁–C₄)haloalkoxyand (C₁–C₄)alkylthio; the chlorinating agent is selected from the groupconsisting of chlorine, salts of hypochlorous acid, phosphoruspentachloride, phosphoryl chloride and thionyl chloride, wherein thechlorinating agent is employed in an amount of 1 to 100 equivalentsbased on the compound of formula (II); and the essentially anhydrousprotic solvent is a carboxylic acid.
 16. The process as claimed in claim15, wherein R² and R³ are in each case independently of one another arehydrogen, acetyl, amino or methyl.
 17. A process for the preparation ofa herbicidal aminotriazine of the formula (IV) or a salt thereof:

which comprises chlorinating a 2-amino-4-thio-1,3,5-triazine of theformula (II):

to give a compound of the formula (I):

and reacting the resulting compound of the formula (I) with an amine ofthe formula (III):A—NH—R  (III) to give the herbicidal aminotriazine of the formula (IV),where in formulae (I), (II), (III) and (IV), the radicals R¹, R², R³ andX are as defined in claim 1 and A and R are organic radicals which inconjunction with the residual molecular structure of the formula (IV)constitute the chemical structure of a herbicidally activeaminotriazine.
 18. The process as claimed in claim 17, wherein A is a(C₁–C₆)alkylene chain which is substituted in the α-position relative tothe amino group by an unsubstituted or substituted alkyl radical and inthe ω-position by an optionally substituted aryl, heteroaryl, aryloxy orheteroaryloxy radical and which is further unsubstituted or substitutedfurther with substituents selected from the group consisting of halogen,alkyl, alkoxy and hydroxyl, and R is hydrogen or alkyl.